Gates

ABSTRACT

APPARATUS OF THE FREE PASSAGE GATE TYPE FOR PROVIDING ACCESS THROUGH PASSAGES AT WHICH PAYMENT IS TO BE MADE. THE PASSAGE IS CONSTITUTED BY A SPACE BETWEEN TWO BOXES WHICH CARRY GATE MEMBERS ADAPTED TO CLOSE THE PASSAGE, AND A CIRCUIT IS PROVIDED FOR OPERATING THE GATE. THIS CIRCUIT IS ARRANGED SO AS TO LEAVE THE GATE OPEN WHEN A USER HAS OBTAINED A TICKET FOR ENTRY, AND TO CLOSE THE GATE WHEN A USER TRIES TO PASS WITHOUT HAVING OBTAINED THIS RIGHT OF ENTRY, AND TO LEAVE THE GATE CLOSED WHEN AT LEAST ONE USER, NOT HAVING PAID, IS IN THE PASSAGE AND ONE USER IS GETTING HIS OWN TICKET, THE GATE REMAINING CLOSED UNTIL THE PASSAGE IS VACATED.

Oct. 5, 1971 BERL 3,609,914

Filed Sept. 5, 1969 2 Sheets-Sheet l Oct. 5, 1971 B. BERL 3,609,914

GATES Filed Sept. 5, 1969 2 Sheets-Sheet 2 United States Patent Ofice 3,609,914 Patented Oct. 5, 1971 3,609,914 GATES Bernard Berl, Paris, France, assignor to Etablissements Georges Klein Filed Sept. 5, 1969, Ser. No. 855,551 Claims priority, application France, Sept. 6, 1968,

Int. c1. Ebsr /20 US. Cl. 49--35 18 Claims ABSTRACT OF THE DISCLOSURE Apparatus of the free passage gate type for providing access through passages at which payment is to be made. The passage is constituted by a space between two boxes which carry gate members adapted to close the passage, and a circuit is provided for operating the gate. This circuit is arranged so as to leave the gate open when a user has obtained a ticket for entry, and to close the gate when a. user tries to pass without having obtained this right of entry, and to leave the gate closed when at least one user, not having paid, is in the passage and one user is getting his own ticket, the gate remaining closed until the passage is vacated.

The invention relates to apparatus of the barrier gate type which allow access through passages at which payment is to be made. It relates more particularly, since it is in this case that its application would seem to be of most interest, but not exclusively to apparatus of the free passage type, that is those which, in normal use, are open to allow the users to pass according to rule, but which are closed when a user (generally a passenger) appears without having obtained his ticket, or should occasion arise, in the wrong direction.

According to the present invention, an apparatus of the free passage gate type for providing access through passages at which payment or the like is to be made, the passages being constituted by a space between two boxes or the like which carry closing members or gates adapted to close the passage, comprises a circuit for operation of the gate arranged so as to leave open the gate when a user has obtained a ticket for entry, and to close the gate when a user tries to pass without having obtained this right of entry, and to leave the gate closed when at least one user, not having paid, is in the passage and one user is getting his own ticket, the gate remaining closed until the passage is vacated.

In addition to the above features, the invention may also include others, all or some of which may be used simultaneously but which if necessary may each be taken separately or in combination with at least one of the others. These are:

The control circuit may be constructed so as to close the gate when a user enters in the wrong direction if a user having obtained his own ticket and being in process of passing through is not present;

At least one network or screen of light beams may be provided, which come preferably from the same light source and on the one hand are arranged to occupy the whole width of the passage and on the other hand, occupy a part at least of the longitudinal space extending between the gate and one end of the passage;

On each side of the gate there may be provided a registering member (for example by photoelectric cells), these members being constructed such that, at least in one of the two directions, the user may be registered at the moment when he passes the gate, by the two members simultaneously, either by means of a calculated delay between the two members, or by a direct and simultaneous registration of the user by both members;

On the exit side of the passage at least two separate registering devices may be arranged substantially one above the other; a member for closing the passage may be constituted by two pivotable arms, adapted to be lodged, in the open position of the gate, respectively in the two boxes defining the passage, the arms preferably occupying their inactive positions when the passage is open.

The invention is further described, by way of example, with reference to the accompanying drawings in which:

FIG. 1 is a diagrammatic perspective view of an apparatus of the gate type according to the invention,

FIG. 2 shOWs an electrical control circuit of a gate,

FIG. 3 is a perspective view of arms for two adjacent passages provided according to the invention,

FIG. 4 shows diagrammatically the arrangement of arms, such as those in FIG. 3, inside a single passage and in a closed position.

Referring to FIG. 1 of the drawings, a passage 3 for users consists of a space between two longitudinal boxes 1 and 2 (shown in outline) which are spaced for example 0.5 m. apart. At least one of the boxes contains in its central part an aperture 4 for a closing member or gate 5 which serves to close the passage 3, and which may be of any form, for example a telescopic barrier or, as will be seen later, pivotable. In the embodiment illustrated, one side of the apparatus is defined as an entrance A and the other side as an exit B.

Means for registering the presence of a user are provided on the boxes 1 and 2. According to one feature of the invention, these means comprise at least one network or screen of light beams forming a barrier, which occupies the whole width of the passage 3 and extends from a side of the gate 5. In FIG. 1 are shown two screens of light rays 6 and 7 situated one on each side of the gate 5 and respectively on the sides A and B thereof. These screens comprise light beams emitted by light sources 8 and 9, the beams being successively reflected by mirrors 10 and 11 so as to activate photoelectric cells 12 and 13 of the photoresistant type. The light sources 8 and 9 and the cells 12 and 13 are preferably all situated in the same box, for example the box 2. Moreover, the screens of light beams are sufliciently close together to prevent a user from stopping between two consecutive beams and thus not interrupting either screen whilst passing through the passage 3.

On the exit side B, a second registering device which according to the invention comprises at least two components situated approximately one above the other is provided, with a view to counting the numbers of users passing through.

In FIG. 1, two lamps 22 and 23 are shown on the box 2, the beams 24, 25 from the lamps 22 and 23 after re fiection from mirrors 26 and 27 on the box 1, serving to activate two photoelectric cells 28 and 29 respectively also of the photoresistant type. The lower component comprising the lamp 23, mirror 27 and photoelectric cell 29 is situated slightly above the ground, while the upper component comprising the lamp 22, mirror 26 and photoelectric cell 28 is situated at the upper extremity of the boxes. The cells 28 and 29, mirrors 26 and 27, lamps 22 and 23 and beams of this second registering device are located in a vertical zone defined by the screen 7.

In order to control the working of the gate, an electric circuit is used according to the invention which, in the method of application considered (gate with free passage) is arranged so as to leave open the gate 5 when a user has paid for his ticket; to close the gate 5 when a user appears without having paid, and to leave it closed when at least one user not having paid has entered the passage 3 and one user is paying his own fee, the gate 5 remaining closed until the passage 3 is empty.

For this purpose, a circuit such as that shown in FIG. 2 is used, which is controlled by the two photoelectric cells 12 and 13 of FIG. 1. In FIG. 2, M designates a motor, an electromagnet or other driving member which, when it is excited, actuates the gate 5 whereby to close the passage 3. The motor M is supplied with a high tension source HT through a normally open switch 14a, the closing of which is caused by excitation of a relay 14. Thus the gate 5 is closed when the relay 14 is excited.

The photoelectric cells 12 and 13, when the light beams 6 and 7 are interrupted cause, possibly after amplification (not shown), the excitation of relays 16 and 17 which are fed by continuous low tension sources BT and BT;,. The relay 16 operates a normally open switch 16:: and the relay 17 operates two coupled normally open switches 17a and 17b.

Authorisation for passage through the apparatus is provided by a memory device, represented diagrammatically by a block 18, which can receive orders through lines 19 and 20. The line 19 transmits signals from a controller (not shown) which serves to detect tickets, tallies, cards, or the like, presented at 21 at the entance A to the apparatus (FIG. 1). The line 20, on the contrary, transmits signals from the photoelectric cells 28 and 29 each time that the beams 24 and 25 are simultaneously interrupted. Thus, the memory device 18 can record several authorisations for passage and, each time that a user is registered by the cells 28 and 29, after his passage through the apparatus the record in the memory device 18 decreases by one unit to zero. The record in the memory device 18 is transmitted (for example by way of relays) by a two way rocking switch 30 which can switch between two positions a and b corresponding respectively to a zero record and a positive record in the memory device 18.

At the terminals C, D of a continuous low tension supply BT there branch off successively in series the switch 16a, the switch 30 (in position a), a relay 31 and the relay 14. The relay 31 carries a self-feeding circuit 32, having a switch 31a operable by the relay 31, connected at E and F in parallel to the switch 30 (in position a).

It may be seen that if a user present himself without paying (record in memory device nil, thus switch 30 in position a) at the entrance screen 6, he closes the contact 160 (by way of the relay 16) and current passes into the branch C, 16a, 30 (in position a), 31, 14, D; the relay 14 closes the contact 14a, which causes the closure of the gate 5 in front of the defrauder by the motor M. On retracing his steps, the defrauder opens the contact 16a and the circuit returns to its initial state. In order to prevent a user in good faith being taken for a defrauder by his interrupting cutting the entrance screen 6 before paying, the toll slot 21 should be placed slightly in advance of the lamp 8.

Moreover, the lamp 8 and the cell 13 will be placed far enough from the gate 5 for the gate 5 to have time to close in front of a defrauder.

The purpose of the relay 31 is to prevent a user who pays his proper admission fee from losing his rights if a defrauder has already entered in the direction A. It is not possible for the user, on paying, to open the gate 5 in front of the defrauder as, in this case, when the record in the memory device 18 becomes positive, the switch 30 passes into position b, but the relay 31 is maintained by its circuit 32, 31a and the gate 5 remains closed. The defrauder must then move back (as previously described) and the payer then has a free passage. The gate is opened as soon as the defrauder has come out, since the relay 31 is cut out by the opening of the contact 16a. When the payer has passed, the contact 16a is closed, but the relay 31 remains inactive, since its terminal F is not connected to the terminal C and in consequence the gate 5 remains open.

In the embodiment shown, and according to another feature of the invention, the circuit is such that a user presenting himself in the exit direction B closes the gate 5 if there is no user in the entrance A who has paid and is in the passage 3. In this case, between a terminal G connected to the supply terminal C and a terminal H situated between the relays 31 and 14, a circuit is provided which contains the switch 17b and a two way rocking switch 33a, the common contact of the latter being connected to the terminal G. Thus when a user presents himself from the side B, he intercepts the beam 7, which activates the relay 17 and closes the switch 17 b. A current flows through the circuit C, G, 33a, 17b, H, 14, D and the contact 1401 is closed, thus causing the closure of the gate. When the defrauder moves back, he opens the contact 17b and the gate opens.

As may be seen, the relay 14 functions alone or in series with the relay 31 under the feed voltage. Thus either a compensating resistance between the switch 33a and the point H, or a central terminal on the relay coil, must be provided.

The contact 33a is operated by a relay 33. This relay serves to allow a user who has duly paid to pass the screen 7 without causing closure of the gate 5 as described above. In other words, the relay 33 neutralises the eifect of interruption of the screen 7 for a user who has duly paid and is passing in the direction A. In this case, the screens 6 and 7 are arranged so that a user who passes in the direction A must be still within the screen 6 at the moment when he enters the screen 7. As may be seen on FIG. 1, the cell 12 and the lamp 9 are located in the immediate neighbourhood of the gate 5 in order that the two screens may be interrupted by a user at the same time.

The relay 33 is connected between a terminal I situated between the switches 17a and 30 and a terminal I connected ot the supply terminal D. When a user has paid and has entered the passage from the direction A, the switch 30 is in position b positive record in the memory device 18 and passes a current into the circuit C, G, 16a, E, 30 (in position b), I, 33, J, D. The switch 3301 thus moves into position b by virtue of excitation of the relay 33. The circuit remains in this state as long as the user is only registered by the cell 12. When the user passes the gate 5. he also interrupts the screen 7, thereby causing closure of the switches 17a and 17b. On advancing, the user passes the screen 6, thereby opening the switch 16a, but the relay 33 remains excited by the circuit C, G, 33a (in position b), 17a, 1, 33, J, D and, in consequence, the effect of the switch 17b is cancelled by virtue of the position b of the switch 33a. The user then finds himself in the icreen 7 without the gate 5 having closed again behind At the same time, the subtraction process is eifected whereby the record in the memory device 18 is reduced by one unit (as will be further described) and, according to the remaining record in the memory device 18, the switch 30 remains in the position b corresponding to a positive record or returns to the prohibiting position a for a zero record. In the latter case, a user presenting himself in the direction A and not having paid, closes the switch 16:: and the relay 14 is excited by way of the circuit C, G, 16a, E, 30 (in position a), 31, 14, D, which causes the gate to close even if the previous user has already passed and finds himself again registered by the screen 7. In other words it is not necessary for a user to have cleared the passage for another to be able to pass through. The operation is also the same if two users are registered at the same time by the beam 6, that is, if the contact 16a remains closed when the first user clears the gate 5. If the second user has not paid, the gate will close as soon as the first user has passed through.

When the user leaves the passage 3, he moves out of the screen 7, which causes the opening of the switch 17a and consequently deactivates out the relay 33, causing the switch 33a to move into position a.

The subtraction process which has been briefly referred to above, is brought about by the Cells 28 and 29 so that a signal to reduce the record is sent to the memory device 18 by the line as soonas the beams 24 and are simultaneously interrupted. A single signal is sent if, after the interruptions are initially simultaneous, one of the beams 24 and 25 is freed and later interrupted again, although the other beam remains interrupted. Further, the subtraction process will preferably only take place if a user enters the entrance screen 6 and remains in the passage 3. This has the advantage of preventing a user who has paid his toll and who has not entered the passage 3 from having his passage cancelled by another user who might try to pass in the direction B. In this way, said other user is not able to pass since the gate is closed in front of him and, in addition, he does not actuate the subtraction process.

In order to obtain this result, the circuit shown in FIG. 2 may be used wherein the two cells 28 and 29, which are photoresistant, are mounted in series with a relay 34, possibly after amplification (not shown), the outlet from the relay 34 being the line 20 which controls the memory device 18. The series circuit containing the two cells 28 and 29 is shunted through a self-feeding branch 35 of the relay 34, in which are included, on the one hand, a maintenance switch 340 operated by the relay 34 and, on the other hand, a normally open switch 36, which is closed when one at least of the cells 28 and 29 is conducting (that is, when one at least of the beams 24 and 25 is interrupted). This circuit is connected to the supply terminal C by way of the terminal I, and to the terminal D by way of the memory device 18.

Starting from the inactive state of the circuit (that in FIG. 2), suppose that a user pays for his ticket but does not enter the passage 3; only the switch is activated and passes into position b, since the record in the memory device becomes positive. If a defrauder then tries to pass in the direction B, he interrupts the screen 7 and closes the gate 5 in front of him through the circuit C, G, 33a (in position (1), 17b, H, 14, D, as described above, but although he cuts the beams 24 and 25, he does not reduce the record in the memory device 18 since the point I is insulated from the terminal C but is, on the contrary, at the potential of the terminal D by virtue of the relay 33 which is inactive. The subtraction process does not therefore occur and the user who has paid does not lose his rights.

Once the defrauder, has left the passage, the user who has paid enters in the direction A, interrupts the screen 6, then the screen 7 and leaves the screen 6. Before the subtraction process, the switch 30 is in position b, the switch 16a is open, the switches 17a and 17b are closed and the relay 33 is excited by its maintenance branch C, G, 33a (position b), 17a, I, 33, I, D. The point I is then at the potential of the terminal C and the subtraction is made as soon as the two beams 24 and 25 are simultaneously interrupted. When the subtraction is effected, the user is still in the exit screen 7. If the record in the memory device 18 is zero, the switch 30 passes into position a, but the gate 5 does not close, since the relay 14 remains inactive switch 33a in position b (and switch 16a open).

On continuing to advance in the direction A, the user frees the screen 7 and the circuit is put out of action, with the possible exception of the switch 30 which has remained in position b if said record is still positive.

The part played by the two cells 28 and 29 is multiple. On the one hand, they prevent a user who carries a case or parcel in front of him, on account of the narrow width of the passage, from causing subtraction on account of the parcel, although he is still in the entrance screen 6 and it has not yet cleared the gate 5. If the subtraction were affected by a single cell, the gate 5 would close in front of the payer owing to the switch 16a, or else, if the memory device 18 had a record greater than 1, there would be two subtractions if the beam were freed between the parcel and the user himself. On the other hand, once the gate 5 was passed, there could be more than one subtraction per user, for example because of the swinging of arms, passage of the legs, canes, umbrellas or the like. This is why the cells 28 and 29 control a circuit so that the signal for subtraction is only sent to the memory device 18 when the two beams 24 and 25 are interrupted simultaneously, no other order being sent if, after this first coincidence of the interruptions one of the beams 24 and 25 is freed (for example by the passing of a leg), then again interrupted (for example by the other leg).

The actual subtraction is effected in the following way. If only one of the beams 24 and 25 is interrupted, for example, by a parcel carried in front or by the advance of a foot or an arm, the corersponding cell can conduct; the switch 36 is closed but the relay 34 remains inactive, since the switch 34a remains open and the other cell is non-conducting. No subtraction then takes place. On the contrary as soon as the two beams are interrupted, the two cells 28 and 29 conduct and the relay 34 is excited so as to send signal to reduce the record in the memory device 18. At the same time, the two switches 34a and 36 are closed. If one of the beams 24 and 25 is freed (for example by the movement of the legs), one of the cells 24 and 25 becomes non-conducting, but the relay 34 remains excited by virtue of its branch 35 (switch 36 closed by the other cell) and the signal to subtract is maintained. If this beam is again interrupted the two cells 28 and 29 are conducting and the relay 34 remains in its excited state. Finally, when the user 'leaves the exit screen 7, he frees both the beams 24 and 25, which makes the cells non-conducting and opens the switch 36, which puts the relay 34 out of action. If, after having caused subtraction the user again cuts one of the beams 24 and 25 for example by, swinging his arms, a cnae or an umbrella, a single cell is excited but no subtraction results.

In FIGS. 3 and 4 are shown one embodiment of a closing member which, for example, may be controlled by the circuit previously described. In fact, a member for two adjacent passages is shown (FIG. 3). The closing member of a passage comprises two arms 37, connected at their lower ends to two spindles 38 journalled on a frame 39 rigidly fixed in a box or casing (not shown). Thus in each box are arranged two arms 37 each of which constitutes a half-gate for two adjacent passages. The spindles 38 may be rotated by electromagnets 40 by way of bell-crank levers 41, with interposition of damper 42 between the framework 39 and the levers 41. Ratchets 43, operable by the electromagnets 44, lock the spindles 39 in position. The whole is arranged so that, when the electromagnets 40 are inactive, the arms 37 are in an open position, that is withdrawn into their boxes 1 and 2 (FIG. 4). For this purpose a counterweight 45, for example, is provided on each arm 37 to urge the arms 37 towards their open position. The arms 37 themselves comprise cranked tube of low inertia, covered with a protective sheath 46 in order to prevent any accident to non-authorised users on which the arms 37 close. Terminal balls 47 complete the safety of the gate. In addition, the angles formed on the arms 37 prevent the passage being open both above and below the gate when it is closed.

Naturally, the control circuit of FIG. 2 can serve to operate gates diiferent from that which has just been described. In particular, gates of the telescopic type or gates which turn around a vertical axis can be used.

The circuit for controlling the gate can be modified according to need without thereby departing from the scope of the invention. Thus, for example, for an apparatus which operates alternatively in the two directions, it is sufficient, on the one hand, to associate, for example, by switching, the relay 16 with the cell 13 and the relay 17 with the cell 12 and, on the other hand, to provide a second set of beams 24 and 25 for the subtraction process symmetrical with the preceding one. If it is desired to leave the exit free in the direction B, it is sufiicient to abolish the screen 7 and to replace it with a directional cell which annuls the action of the cell 12 when on leaving in the direction B, a user interrupts the screen '6, this being in order to prevent the gate from reclosing behind him. It is also to be noted that if for any reason whatever the arrangement of the apparatus does not allow the user to enter the screen 7 before having left the screen 6, the same result as before can be obtained by the use of a calculated delay of the relays 16 or 33. Finally, for the registering of a user, other members such as carpet switches could be used instead of photoelectric cells, with or without calculated delay between the screens.

Whatever may be the embodiment adopted, an apparatus of the barrier gate type is thus obtained, the functioning of which has been described at length, and which has numerous advantages, namely:

universality of the control circuit which, by simple switching, allows alternatively use in both direction of the passage, with or Without a prohibited direction, reduction of fraud,

the method of subtraction prevents an authorised user from being treated as a defrauder if he carries, for example, a case or if he swings his arms,

preservation of the rights of a user who has paid as compared with a defrauder,

simplicity of the control circuit,

simplicity and economy of use since the gate remains open in normal service and is only closed in case of fraud,

safety in use since, in the case of electrical failure, the

gate remains open.

As a matter of course. and as already follows from the above, the invention is in no way limited to one of its methods of application, nor to the embodiments of its various parts, which have been more particularly considered; on the contrary, it includes all the variants.

What I claim is:

1. Apparatus of the free passage gate type for providing passage to users authorized by valid tickets, said apparatus comprising:

two side-wall means defining a passage having an entrance end and an exit end, gate means housed in said side-wall means and arranged to close the passage under certain conditions,

and gate drive means,

said apparatus comprising also:

detector means arranged to detect the presence in said passage of a user who enters through either of said ends,

sensing means arranged to leave the gate means open on presentation of a valid ticket by a so-authorized user,

said detector means and said sensing means being arranged in combination so as to operate said gate drive means to close the gate means when a user tries to pass without presenting a valid ticket and to maintain the gate means closed as long as an unauthorized user remains in the passage without presenting a valid ticket, even when another user presents a valid ticket during the time that said unauthorized user remains in the passage.

2. Apparatus according to claim 1, comprising a memory device in circuit with said detector means and said sensing means,

a two-way switch controlled by signals from said memory device to occupy an authorised position or a nonauthorised position,

and a system of relays governed by said two-way switch and controlling said gate drive means.

3. Apparatus according to claim 2, comprising:

a holding relay coupled to said two-way switch,

a gate drive control relay coupled to said holding relay,

and

an entrance detector relay controlled by a said detector means at said entrance, arranged to close the gate means and, when the two-way switch is in a nonauthorised position, to maintain said gate means closed by means of said holding relay even when an authorised user presents a valid ticket.

4. Apparatus according to claim 2, comprising an exit detector relay:

a said detector means at said exit controlling said detector relay, and

at least one second relay adapted to enable the gate to close when said exit detector relay indicates that a user is present in the exit, except when an authorised passenger is present in the entrance.

5. Apparatus acording to claim 4, including a second two-way switch, actuated by said second relay and arranged to switch current through one or other of two contacts controlled by said exit detector relay.

6. Apparatus according to claim 1, wherein said detector means comprise at least one light source providing a net- Work of light beams, photocells coacting with said light beams to monitor the major part of the respective spaces between the gate and the ends of said passage.

7. Apparatus according to claim 1, wherein said detector means comprise carpet switches.

8. Apparatus according to claim 1, wherein said detector means comprise calculated delay devices.

9. Apparatus according to claim 1, wherein said detector means are arranged on both sides of the gate, comprise entrance detector means and exit detector means, and include time delay means arranged so that as soon as an authorised user has passed through the gate, the latter is not prematurely closed by actuation of said exit detector means.

10. Apparatus according to claim 9, wherein said time delay means is constituted by suitable positioning of said detector means.

11. Apparatus according to claim 9, wherein said time delay means is constituted by a time delay device in circuit with said exit detector means.

12. Apparatus according to claim 10, wherein said detector means are positioned in neighboring locations on each side of the gate, said locations being such that an authorised user passing through the gate is still influencing said entrance detector means when he influences the exit detector means.

13. Apparatus according to claim 2, wherein the detector means include in the passage on the exit side two separate detectors arranged to effect cancellation of signals stored in said memory.

14. Apparatus according to claim 13, wherein said two separate detectors comprise photoelectric cells arranged one above the other and adapted to eifect said cancellation only when simultaneously influenced.

15. Apparatus according to claim 13, wherein said memory is arranged to receive add signals from said ticket sensing means and subtract signals from said two detectors.

16. Apparatus according to claim 14, wherein said photoelectric cells are arranged in series with a relay connected to the memory, the series circuit formed by said two photoelectric cells being in parallel with a supply References Cited connection to said relay and including a switch, normally UNITED STATES PATENTS open, which is closed when said one of said photoelectric cells is influenced. 3,169,329 2/ 1965 Powers 4935 17. Apparatus according to claim 6, wherein said net- 5 3,386,202 6/1968 Crews et a1 4935 work is provided by one light source, mirrors being posi- 3,519,993 7/ 1970 Sakai et a1. 4935 X t' d' 'dd-llt fitth l'htb 23 Sal 81 e w S 0 R as e lg eams Sue J. KARL BELL, Primary Examiner 18. Apparatus according to claim 17, wherein said light US Cl XR.

source and said puhotocells are placed in a same side- 10 wan. 49-25, 340149 

